Spider-silk inspired polymeric networks by harnessing the mechanical potential of β-sheets through network guided assembly

Abstract

The high toughness of natural spider-silk is attributed to their unique β-sheet secondary structures. However, the preparation of mechanically strong β-sheet rich materials remains a significant challenge due to challenges involved in processing the polymers/proteins, and managing the assembly of the hydrophobic residues. Inspired by spider-silk, our approach effectively utilizes the superior mechanical toughness and stability afforded by localised βsheet domains within an amorphous network. Using a grafting-from polymerisation approach within an amorphous hydrophilic network allows for spatially controlled growth of poly (valine) and poly(valine-r-glycine) as β-sheet forming polypeptides via N-carboxyanhydride ring opening polymerisation. The resulting continuous β-sheet nanocrystal network exhibits improved compressive strength and stiffness over the initial network lacking β-sheets of up to 30 MPa (300 times greater than the initial network) and 6 MPa (100 times greater than the initial network) respectively. The network demonstrates improved resistance to strong acid, base and protein denaturants over 28 days.

Bio-Inspired Polymer-Polymer Hybrids for Medical Applications

“…The results showed that the created network has significantly better compressive strength and stiffness being a 300-and 100-fold improved over the original network. Additionally, the hybrid network has demonstrated the resistance to acids, bases and protein denaturants [110].…”

Chemical control of peptide material phase transitions

“…Naturally occurring silks contain ordered β-sheet domains for strength dispersed within a flexible disordered protein matrix. 1 Such disorder in polymeric materials may arise from subtle quantum defects and/or large scale conformational and covalent heterogeneities, 2,3 all contributing to the material properties. Living systems have evolved special strategies to exploit this property.…”

Chemical Control of Peptide Material Phase Transitions

“…Naturally occurring silks contain ordered b-sheet domains for strength dispersed within a exible disordered protein matrix. 1 Such disorder in polymeric materials may arise from subtle quantum defects and/or large scale conformational and covalent heterogeneities, 2,3 all contributing to the material properties. Living systems have evolved special strategies to exploit this property.…”